Key LLC Tax Deadlines in 2025

As a small business owner, compliance with tax deadlines is a critical aspect of your responsibilities. Businesses must file income tax returns to avoid fines and penalties. Unfortunately, the LLC tax rules can be confusing.

The LLC tax form and due date vary depending on the company’s business structure. Knowing which tax form to file – and when – can be challenging for business owners juggling multiple priorities.

This article will explain the 2025 LLC tax deadlines for federal tax returns, extensions, and quarterly estimated tax payments. We’ll also explain how your entity type determines your federal income tax filing requirement and how a fiscal year affects your LLC tax deadlines.

What Is an LLC – and Why Is This so Complicated?

A limited liability company (LLC) is a legal business entity established under state laws. An LLC structure offers benefits for its owners, including limited liability protection and a distinct business identity. 

LLCs can also provide tax benefits depending on the business activities. For example, LLCs have a flexible tax structure, allowing owners to elect alternate federal income tax treatment.

LLC tax forms and deadlines depend on the entity’s tax elections (if any) and the number of business owners. LLCs follow the tax treatment of one of the following entity types: 

• Sole proprietorship

• Partnership

• S corporation

• C corporation

LLC Federal Income Tax Due Dates

Your small business tax structure determines your LLC’s federal tax return form and filing deadline. 

Calendar year taxpayers file income tax returns by March 15th or April 15th, depending on the entity type. The deadline shifts to the next business day if a due date falls on a weekend or holiday.

The LLC federal tax return due dates in 2025 are as follows: 

• Partnerships and S corporations: The due date for tax year 2024 returns is March 17th, 2025.

• Sole proprietorships and C corporations: The due date for tax year 2024 returns is April 15th, 2025.

Additionally, sole proprietorships and C corporations must make quarterly estimated income tax payments throughout the year. 

Taxpayers should review their year-to-date business income and make payments toward the current year’s tax liability. For example, a freelancer’s Q2 2025 estimated payment applies towards the 2025 tax bill.

The following are the 2025 quarterly tax payment due dates:

• First quarter: April 15th, 2025

• Second quarter: June 16th, 2025

• Third quarter: September 15th, 2025

• Fourth quarter: January 15th, 2026

Not sure how much to pay? Use 1-800Accountant’s free Quarterly Estimate Calculator for a guideline. Consult with tax professionals for specialized calculations.

The following table summarizes the 2025 LLC federal income tax deadlines for each business entity type.

Fiscal Year and LLC Tax Due Dates

LLCs default to a calendar year for tax purposes, meaning their tax returns must report activity from January 1st – December 31st. However, taxpayers meeting the IRS eligibility requirements can apply to use a fiscal year. 

A fiscal year uses a financial statement period other than a calendar year. Small businesses can use fiscal year reporting to align with revenue trends or seasonality. For example, many retailers use a February 1st – January 31st fiscal year due to increased sales volumes during the holiday season.

Fiscal years commonly end on March 31st, June 30th, or September 30th. Some taxpayers prefer a 52-53 week year, which always ends on the same day of the week, such as the last Friday in December.

Fiscal year LLCs comply with different federal income tax deadlines than calendar year taxpayers follow. Refer to the following guidelines to determine your fiscal year tax return due dates. 

• Partnerships and S corporations: The 15th day of the third month after the company’s year-end. For example, a June 30th year-end taxpayer must file by September 15th.

• Sole proprietorships and C corporations: The 15th day of the fourth month after the company’s year-end. For example, a June 30th year-end taxpayer must file by October 15th. 

Taxpayers can file Form 1128 to apply for a fiscal year-end. We recommend consulting tax professionals to determine whether you meet the eligibility requirements. 

Personal Tax Filing Deadline vs. Business Tax Deadline

As we’ll explain later, most businesses file returns separately from their owners. However, sole proprietors must file their personal and business returns together. Sole proprietors report their small business activity on schedules attached to their individual income tax return forms. 

Other business entities file returns to report business activity, while the owners file separate personal tax returns. 

Other LLC Business Tax Deadlines

Your LLC may need to file additional tax forms, depending on your business location and operations. 

The forms and due dates for other business taxes vary. Consider the following tax types that could apply.

Employment Tax Form Deadlines

LLCs hiring independent contractors or employees must file certain employment forms annually by January 31st.

Employers with full- or part-time employees must submit IRS Form W-2, Wage and Tax Statement, to report employee wages and tax withholding. Businesses must also provide a W-2 to every employee with their withholding tax information. W-2 transmissions must include IRS Form W-3, Transmittal of Wage and Tax Statements. 

LLCs hiring freelancers may need to file 1099 forms with the IRS. 1099s report certain types of business payments. The following forms report payments to nonemployees.

• IRS Form 1099-MISC, Miscellaneous Information: Payments for royalties, rent, attorney fees, and other items

• IRS Form 1099-NEC, Nonemployee Compensation: Payments to freelancers or independent contractors 

Employers must file W-2s and 1099s by January 31st. This deadline applies to calendar-year and fiscal-year filers.

State Taxes

Many LLCs must file state and local business taxes, such as state income tax, sales and use, property, and payroll taxes.

State income tax deadlines generally align with federal income tax due dates. Rules vary, but most state income tax returns are due by the federal return deadline or 1-2 months later.

Sales, property, and payroll tax returns have monthly, quarterly, or annual due dates.

We recommend partnering with state tax experts who can help you comply with your state’s laws.

Types of LLCs and How to File

Single-Member LLC: Sole Proprietorship

LLCs owned by one individual, called single-member LLCs, default to sole proprietorships for federal tax purposes.

Sole proprietors must report their LLC’s business activity on Schedule C, Profit or Loss from Business (Sole Proprietorship).

Additionally, sole proprietors must pay self-employment tax on their business income. Self-employment tax covers Social Security and Medicare taxes. Taxpayers should use Schedule SE (Form 1040), Self-Employment Tax, to compute the self-employment tax liability.

Business owners file Schedule C and Schedule SE as attachments to IRS Form 1040, U.S. Individual Income Tax Return.

Sole proprietors must file personal income tax returns by April 15th, 2025.

Don’t let your LLC taxes add stress to your tax season. Partner with 1-800Accountant for your sole proprietor return preparation and filing.

Passthrough Entity Taxation

Partnerships and S corporations are passthrough entities for federal income tax purposes. 

Passthrough entities do not pay federal income tax on business income. Instead, multi-member LLCs pass profits and losses to the business owners. The owners must report their share of business activity on their income tax returns.

Passthrough entity tax forms represent information returns, which report business activity, assets, and ownership information. 

Multi-Member LLC: Partnership 

LLCs with multiple owners, called multi-member LLCs, default to partnership taxation. Partnerships file IRS Form 1065, U.S. Return of Partnership Income, to report business income and expenses.

Additionally, partnerships file Schedule K-1s, which report each partner’s ownership and share of business activity. The LLC must provide each partner with their Schedule K-1. Business owners report their share of the LLC’s income and expenses on their personal income tax returns.

Multi-member LLCs must file Form 1065 and Schedule K-1s by March 17th, 2025.

LLC with S Corp Election: S Corporation

A single- or multi-member LLC can file an S corporation election, which converts the LLC to an S corp for federal tax purposes. (Note: the LLC must file a corporate tax election before filing an S corp election.) 

Like partnerships, S corporations follow passthrough entity tax treatment.

S corporations file IRS Form 1120-S, U.S. Income Tax Return for an S Corporation. Form 1120-S reports business activity and ownership information. S corps must also file Schedule K-1s to report each member’s ownership and share of business activity.

S corporations must file Form 1120-S and Schedule K-1s by March 17th, 2025.

LLC with Corporate Tax Election: C Corporation

A single- or multi-member LLC can file an entity classification election to convert to corporate tax treatment.

C corps represent separate legal entities that pay federal income tax on corporate profits. C corp owners avoid self-employment tax on the company’s income, but shareholders face double taxation. The C corporation pays corporate tax on its business income, and the business owners pay individual income tax on dividend income.

C corps file IRS Form 1120, U.S. Corporation Income Tax Return. Corporate tax returns report business income, expenses, and numerous other items, depending on the company’s operations.

C corporations must file Form 1120 by April 15th, 2025.

Regardless of your LLC tax treatment and return deadline, partnering with 1-800Accountant for your business tax preparation can take time-consuming paperwork off your hands.

How to File a Tax Extension as a Small Business Owner

Regardless of your business structure, your LLC can request a six-month extension of time to file its federal income tax return. Extensions are due by the federal tax return deadline.

Sole proprietors file IRS Form 4868, Application for Automatic Extension of Time to File U.S. Individual Income Tax Return. Partnerships and corporations file IRS Form 7004, Application for Automatic Extension of Time To File Certain Business Income Tax, Information, and Other Returns.

Extensions grant six months of additional time to file federal tax returns. Your extended LLC tax return due date depends on your business entity type: 

• Partnerships and S corporations: The extended due date for tax year 2024 returns is September 15th, 2025.

• Sole proprietorships and C corporations: The extended due date for tax year 2024 returns is October 15th, 2025.

LLC owners should understand that extensions grant additional time to file, not time to pay. Your LLC must estimate and pay its entire federal tax liability before the original return deadline. 

Consider partnering with professional CPAs for help with filing your LLC tax extension and paying your estimated tax liability. 

LLC Tax Deadline FAQ

What Happens If You Miss the Tax Filing Deadline and the IRS Owes You a Refund?

If your small business misses a deadline and expects a refund, you may avoid failure to file penalties. However, your LLC should file as soon as possible to avoid forfeiting the tax refund.

What Happens If You Miss the Deadline and Owe Taxes?

The IRS imposes failure to pay penalties on taxpayers who make delinquent tax payments. To avoid penalties and interest, file your LLC tax return by the due date.

What Happens If You Miss an Estimated Tax Payment Deadline?

The IRS imposes failure to pay penalties on taxpayers who make delinquent tax payments. To avoid penalties and interest, comply with quarterly estimated tax due dates and submit payments timely.

Partner with Experts to Lower Your LLC Tax Bill

Hitting deadlines and calculating accurate tax estimates requires time and effort. LLC business owners and entrepreneurs can avoid tedious paperwork by partnering with 1-800Accountant. 

1-800Accountant can help your LLC comply with complicated tax laws and avoid penalties. Professional CPAs offer tax filing and preparation services to save you time and support your business. Tax experts can help your LLC maximize tax deductions and lower your tax liability.

For ongoing tax planning, 1-800Accountant’s year-round advisory services help with entity formation and financial planning.

Schedule a free consultation with 1-800Accountant to learn how we can support your small business.